This invention relates to derivatives of alpha-amino acid amides, to pharmaceutical compositions containing such compounds, and to their use in medicine as inhibitors of cysteine proteases, particularly the cathepsins.
The cathepsin family (C1) of lysosomal cysteine (or thiol) proteases is a subset of the papain superfamily (clan CA of cysteine proteases) and includes cathepsin B, H, K, S, L and the recently discovered cathepsins O, O2/K, V, X, Z and W (lymphopain). Related enzymes also regarded as cysteine proteases are the cytoplasmic Ca2+ dependent calpains (family C2). Cysteine proteases are classified both functionally and according to the nature of their active site, which has a thiol residue. They differ in substrate specificities and other enzymatic activities, these differences probably arising from evolutionary divergence.
The known cathepains are synthesized on membrane bound ribosomes, transferred to the endoplasmic reticulum, then to the Golgi apparatus and finally to the lysosome and endosomes. They have an important function in regulation of intracellular protein metabolism, mobilisation of tissue proteins and conversion of proenzymes, prohormones and neuropeptides into biologically active molecules. The cathepsins are believed to be involved in a number of diseases.
Cathepsin K can be secreted into the extracellular space and is involved in bone and cartilage remodelling. Cathepsin K is implicated in the pathogenesis of osteoporosis. Cathepsin K inhibitors can prevent osteoporosis in animal models (PNAS.1997. 94:14249-14254). Cathepsin L inhibitors have also been shown to inhibit osteoporosis (Bone, 1997. 20:465-471).
Cathepsin B and other cysteinyl cathepsins have also been shown to be released extracellularly by various tumour cells and are thought to play a role in tumour invasion (Journal of cellular Physiology. 1992. 150:534-544).
The cysteinyl cathepsins have also been shown to play a role in rheumatoid arthritis (Arthritis and Rheumatism 1994. 37:236-247) and neuronal and cardiac ischaemia (European Journal of Neuroscience. 1998. 10.1723-1733).
Cathepsins S and L both play a role in the generation of free MHC class II molecules capable of binding antigenic peptides in the endosomes. These class II/peptide complexes move to the cell membrane and are involved in T lymphocyte activation. Inhibitors of Cathepsin S have been shown to inhibit allergic immune responses (Journal of Clinical Investigation. 1998. 101:2351-2363).
In addition to their role in the above diseases, cysteinyl cathepsins play a major role in the pathogenesis of infectious diseases. For example, cysteinyl cathepsins are used by the protozoal parasites Plasmodium (malaria) and Trypanosoma (Chagas Disease) to invade the human host and cysteinyl cathepsin inhibitors can inhibit experimental disease in both cases (Antimicrobial agents and chemotherapy. 1998. 42:2254-2258; Journal of Experimental Medicine. 1998. 188:725-734). Cysteinyl cathepsins are also virulence factors for several pathogenic bacteria.
A recent review (Annu. Rev. Physiol. 1997. 59:63-88) describes the state of the art of cysteine proteases, including the cathepsins, and their presumed biological functions. Other reviews deal with cathepsin B inhibitors as potential anti-metastatic agents (Exp. Opin. Ther. Patents, 1998, 8: 645-672), and cathepsin K inhibitors as potential treatments for osteoporosis (Exp. Opin. Ther. Patents, 1999, 9: 683-644).
International patent applications WO 96/32408, WO 98/12176, WO 98/12210 and GB 9806287.0 describe, inter alia, classes of cysteine protease inhibitors which may be represented by formula (IA): 
wherein Y, R1, R2 and R3 represent the groups found in corresponding positions of the compounds disclosed in those publications. These known compounds are azetidin-2-ones which are monosubstituted at positions 3 and 4.
The present invention makes available a new class of cysteine protease inhibitors which differ in structure from those disclosed in WO 96/32408, WO 98/12176, WO 98/12210 and GB 9806287.0 principally in that the azetidin-2-one ring is replaced by a substituted carbonylmethyl moeity, as more fully explained below. These compounds are useful for the treatment of diseases mediated by cysteine protease activity, for example muscular dystrophy, osteoporosis, tumour metastasis, rheumatoid arthritis, neuronal or cardiac ischaemia, allergic immune response, and protozoal or bacterial disease.
According to the present invention, there is provided a compound of formula (I) 
wherein:
Y represents xe2x80x94C(O)xe2x80x94 or xe2x80x94S(O2)xe2x80x94;
R1 represents a radical of formula R6xe2x80x94(ALK)pxe2x80x94(Z)nxe2x80x94(ALK)qxe2x80x94 wherein Z represents xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94, ALK represents a divalent C1-C3alkyl or halogen-substituted C1-C3alkyl radical, p and q are independently 0 or 1, n is 0 or 1 when q is 1 and n is 0 when q is 0, and R6 is hydrogen or an optionally substituted C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, cycloalkyl, cycloalkenyl, aryl or heterocyclic group; or R1 together with the carbon atom to which it is attached forms a cycloalkyl ring;
R2 represents xe2x80x94OR5 or xe2x80x94R5;
R5 represents a radical of formula R7xe2x80x94(A)txe2x80x94 wherein t is 0 or 1; A represents (i) an optionally substituted divalent C1-C6alkyl, radical which may be interrupted by one or more non-adjacent xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94NHxe2x80x94 linkages, or (ii) a divalent C2-C6alkenyl, C2-C6alkynyl, cycloalkyl, cycloalkenyl, aryl or heterocyclic radical, or (iii) a xe2x80x94NHxe2x80x94 link; and R7 represents hydrogen or an optionally substituted C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, cycloalkyl, cycloalkenyl, aryl or heterocyclic group;
R3 represents (i) an optionally substituted C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, cycloalkyl, cycloalkenyl, aryl or heterocyclic group or (ii) NHR8 or N(R8)2 or (iii) OR8 wherein R8 represents hydrogen or an optionally substituted C2-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, cycloalkyl, cycloalkenyl or aryl;
A and B taken together represent a bond and R4 represents a hydroxy or substituted hydroxy group or an amino or primary or secondary amino group, or A represents hydrogen and B and R4 each independently represents a hydroxy or substituted hydroxy group;
or a pharmaceutically acceptable salt, hydrate or solvate thereof.
Pharmaceutically acceptable salts of the compounds of this invention include the sodium, potassium, magnesium, calcium, hydrogen chloride, tartaric acid, succinic acid, fumaric acid and p-toluenesulfonic acid salts.
As used herein the term (C1-C6)alkyl or lower alkyl means a straight or branched chain alkyl moiety having from 1 to 6 carbon atoms, including for example, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylprop-1-yl, 2-methylprop-2-yl, pentyl, 3-methylbutyl, and hexyl. Similar terms such as xe2x80x9c(C1-C3)alkylxe2x80x9d are to be interpreted similarly.
As used herein the term C2-C6alkenylxe2x80x9d means a straight or branched chain alkenyl moiety having from 2 to 6 carbon atoms having at least one double bond of either E or Z stereochemistry where applicable. The term includes, for example, vinyl, allyl, 1- and 2-butenyl and 2-methyl-2-propenyl. Similar terms such as xe2x80x9c(C2-C3)alkenylxe2x80x9d are to be interpreted similarly.
As used herein the term xe2x80x9cC2-C6alkynylxe2x80x9d means a straight chain or branched chain hydrocarbon groups having from two to six carbon atoms and having in addition one triple bond. This term would include for example, ethynyl, 1-propynyl, 1- and 2-butynyl, 2-methyl-2-propynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl and 5-hexynyl. Similar terms such as xe2x80x9c(C2-C3)alkynylxe2x80x9d are to be interpreted similarly.
As used herein the term cycloalkyl means a saturated alicyclic moiety having from 3-7 carbon atoms and includes, for example, cyclohexyl, cycloheptyl, cyclopentyl, cyclobutyl and cyclopropyl.
As used herein the term xe2x80x9chalogenxe2x80x9d means fluoro, chloro, bromo or iodo.
As used herein the term xe2x80x9carylxe2x80x9d refers to a mono-, bi- or tri-cyclic, substituted or unsubstituted, carbocyclic aromatic group, and to groups consisting of two covalently linked substituted or unsubstituted monocyclic carbocyclic aromatic groups. Illustrative of such groups are phenyl, biphenyl and napthyl. Examples include C6-C12 aryl groups such as phenyl, biphenyl, naphthyl, tetrahydronaphthyl, dihydronaphthyl, and cyclohexyl phenyl.
As used herein the unqualified term heterocyclyl or heterocyclic means a 5-7 membered heterocyclic ring, which may be aromatic or non-aromatic, containing one or more heteroatoms selected from S, N and O, and optionally fused to a benzene or hetero-atom containing ring. The term therefore includes C1-C11 heterocyclic groups containing 1-4 heteroatoms selected from nitrogen, sulfur or oxygen. Examples include thienyl, pyridyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,3,4-tetrazolyl, imidazolyl, quinolinyl, isoquinolinyl, indolyl, pyrimidinyl, benzofuranyl, benzothienyl, morpholinyl, thiomorpholinyl, piperazinyl, piperidinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, pyridylphenyl, pyrimidylphenyl, pyrrolyl, furyl, thienyl, piperidinyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, pyrazolyl, pyridinyl, pyrrolidinyl, pyrimidinyl, morpholinyl, piperazinyl, indolyl, benzimidazolyl, maleimido, succinimido, and phthalimido groups.
As used herein, the term xe2x80x9cprimary or secondary amino groupxe2x80x9d means an amino group carrying one or two substituents respectively, for example selected from amino protecting groups, (C1-C6)alkyl-Xxe2x80x94, (C2-C6)alkenyl-Xxe2x80x94, (C2-C6)alkenyl-Xxe2x80x94, aryl(C1-C6)alkyl-Xxe2x80x94, aryl(C2-C6)alkenyl-Xxe2x80x94, aryl(C2-C6)alkenyl-Xxe2x80x94, heterocyclic(C1-C6)alkyl-Xxe2x80x94, heterocyclic(C2-C6)alkenyl-Xxe2x80x94, heterocyclic(C2-C6)alkenyl-Xxe2x80x94, wherein xe2x80x94Xxe2x80x94 represents a bond or a carbonyl xe2x80x94C(O)xe2x80x94, sulphonyl xe2x80x94S(O2)xe2x80x94, or oxycarbonyl xe2x80x94Oxe2x80x94C(O)xe2x80x94 group, and wherein any of the foregoing may be substituted. The term xe2x80x9csecondary amino groupxe2x80x9d also means a substituted or unsubstituted cyclic amino group, such as piperidyl, morpholinyl, thiomorpholinyl, piperazinyl, pyrrolidynyl or azetidinyl.
As used herein, the term xe2x80x9csubstituted hydroxy groupxe2x80x9d means a protected hydroxy group or a hydroxy group substituted by, for example, any of the substituents listed in the preceding paragraph as substituents of primary or secondary amino groups except those wherein X is an oxycarbonyl xe2x80x94Oxe2x80x94C(O)xe2x80x94 group.
As used herein in contexts other than xe2x80x9csubstituted hydroxy groupxe2x80x9d, the unqualified term xe2x80x9csubstitutedxe2x80x9d as applied to a roup or radical means substituted with 1, 2, or 3 ubstituents selected from
(C1-C3)alkyl;
phenyl;
hydroxy or mercapto;
(C1-C3)alkoxy or (C1-C3)alkylthio;
phenoxy or phenylthio;
halogen;
trifluoromethyl;
nitro;
cyano (xe2x80x94CN);
carboxyl, and amidated, esterified or protected carboxyl;
amino, mono- or di-(C1-C3)alkylamino, or protected amino;
(C1-C3)alkylcarbonyl- or (C1-C3)alkylcarbonylamino-;
xe2x80x94CONHRA, xe2x80x94NHRA, xe2x80x94NRARB, or xe2x80x94CONRARB wherein RA and RB are independently (C1-C3)alkyl; and
xe2x80x94NHxe2x80x94C(xe2x95x90NR9)R10 wherein R10 is amino, mono- or di-(C1-C6)alkylamino, protected amino, or (C1-C3)alkyl, and R9 is hydrogen, (C1-C3)alkyl, or an N-protecting group.
As used herein the term xe2x80x9cprotecting groupxe2x80x9d when used in relation to an amino, hydroxy or carboxylic acid moeity in the compounds of this invention means a group which is used to render the amino, hydroxy or carboxylic acid moeity substantially non reactive, ie to neutralise its amino, hydroxy or carboxylic acid functionality. In this context, protected amino groups include amido and acylamino, protected hydroxy groups include ethers, protected carboxyl groups include esters, and imidazolyl, indolyl or guanidyl groups may be protected as t-butoxycarbonyl derivatives. These are only examples of the many protecting derivatives known in the art, and others will be known to the skilled man. Such protecting groups are of course well known, eg from the art of peptide synthesis, and are discussed in the widely used handbook by T. W. Greene and P. G. M. Wuts, Protective groups in Organic Synthesis, 2nd Edition, Wiley, New York 1991, and elsewhere in the chemical literature.
As mentioned above, the compounds of the invention differ in structure from those of WO 96/32408, WO 98/12176, WO 98/12210 and GB 9806287.0 principally in that the azetidin-2-one ring is replaced by a substituted carbonylmethyl moeity. That substituted carbonylmethyl moeity is the radical (II): 
which may be regarded as notionally derived from the aldehyde radical (III): 
The substituents R1 and R2 in the compounds of the invention may be any of the groups falling within the above definitions of R1 and R2 which are present in corresponding positions of cysteine protease inhibitors disclosed in WO 96/32408, WO 98/12176, WO 98/12210 and GB 9806287.0. Without prejudice to the generality of the foregoing, in the compounds of the invention:
Y may be, for example, xe2x80x94C(O)xe2x80x94;
R1 may be, for example, a phenyl group which may be substituted by one or more of hydroxy, halogen, methoxy, methyl, isopropyl, tert-butyl and trifluoromethyl; isopropyl, cyclohexyl; 3-pyridinyl; naphthyl; biphenyl; 2-thienyl; 3,4-methylenedioxyphenyl; 3,4-ethylenedioxy-phenyl; benzothienyl; thiazolyl; quinolinyl; isoquinolinyl; tetrahydroquinolinyl; tetrahydronaphthyl; aminonaphthyl; or acetamidonaphthyl. Presently preferred are phenyl, isopropyl, cyclohexyl and 3-pyridinyl.
R2 may be, for example, benzyloxy, 3-phenylpropyloxy, 3-phenylpropyl, 3-phenylprop-1-enyl, 6-N,N-dibenzyloxycarbonylguanidino-hexyl, 6-guanidino-hexyl, methoxy-methyleneoxy-methyl, 2-amino-ethoxy-methyl, 3-(pyridin-3- or 4-yl)-propyl, or 3-(pyridin-3- or 4-yl)-prop-1-enyl.
R3 may be, for example, methyl, ethyl, isopropyl, t-butyl, cyclohexyl, phenyl, 4-methoxyphenyl, 4-fluorophenyl, pyridyl, xe2x80x94NH2, methylamino, dimethylamino, benzylamino, piperidino, morpholino, piperazino, N-methylpiperazino or methoxy, ethoxy, t-butyloxy or phenoxy.
When A and B taken together represent a bond, R4 may be, for example, xe2x80x94NH2, acetylamino, methylamino, dimethylamino, benzylamino, morpholino, piperidino, morpholino, piperazino or N-methylpiperazino, methoxycarbonylmethylamino, (methoxycarbonyl)-phenethylamino, xe2x80x94OH, methoxy, allyloxy, benzyloxy. Alternatively, A may be a hydrogen and B and R4 each independently represents a hydroxy group.
Specific compounds of the invention include those named and characterised in the Examples herein.
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-amino-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-cyclohexylmethyl-acetamido)-3-amino-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-benzyl-acetamido)-3-amino-acrylamide
2-[2S-2-(3-phenylpropionoyl)amino-2-benzyl-acetamido]-3-amino-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-benzylamino-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-(morpholin-4-yl)-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-(2-hydroxyethylamino)-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-phenylamino-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-piperidino-acrylamide
2E)-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-acetamido-acrylamide
(2Z)-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-acetamido-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3,3-dihydroxy-propionamide
2-(2S-2-benzyloxycarbonylamino-2-cyclohexylmethyl-acetamido)-3,3-dihydroxy-propionamide
2-(2S-2-benzyloxycarbonylamino-2-benzyl-acetamido)-3,3-dihydroxy-propionamide
2-[2S-2-(3-phenylpropionoylamino)-2-benzyl-acetamido]-3,3-dihydroxy-propionamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-hydroxy-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-benzylamino-N-benzyl-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-(4-methylpiperazino)-acrylamide
2-(2S-2-benzyloxycarbonylamino-2-isopropylmethyl-acetamido)-3-(3-tert-butoxycarbonylamino-pyrrolidino)-acrylamide
(2E)-(2S-2-benzyloxycarbonylamino-2-cyclohexymethyl-acetamido)-3-acetamido-acrylamide
(2Z)-(2S-2-benzyloxycarbonylamino-2-cyclohexylmethyl-acetamido)-3-acetamido-acrylamide
tert-Butyl-2-[2S-(benzyloxycarbonylamino)-2-isopropylmethyl-acetamido]-2-(morpholino-1-methylenyl)-acetate
Ethyl-2-[2S-(benzyloxycarbonylamino)-2-isopropylmethyl-acetamido]-2-(4-methylpiperazino-1-methylenyl)-acetate
Ethyl-2-[2S-(benzyloxycarbonylamino)-2-phenylmethyl-acetamuido]-2-(morpholino-1-methylenyl)-acetate
Ethyl-2-[2S-(benzyloxycarbonylamino)-2-isopropylmethyl-acetamido]-2-(morpholino-1-methylenyl)-acetate
Ethyl-2-[2S-(benzyloxycarbonylamino)-2-cyclohexylmethyl-acetamido]-2-(morpholino-1-methylenyl)-acetate
Diphenylmethyl-2-[2S-(3-phenylpropionylamino)-2-phenylmethyl-acetamido]-2-(morpholino-1-methylenyl)-acetate
2-[2S-(Benzothiophen-2-carbonylamino)-2-isopropylmethyl-acetamido]-2-(morpholino-1-methylenyl)-4xe2x80x2-methoxyacetophenone.
2-[2S-(Benzyloxycarbonylamino)-2-isopropylmethyl-acetamido]-2-(morpholino-1-methylenyl)-acetophenone.
2-[2S-(Benzyloxycarbonylamino)-2-isopropylmethyl-acetamido]-2-(morpholino-1-methylenyl)-4xe2x80x2-methoxyacetophenone.
2-[2S-(Benzyloxycarbonylamino)-2-isopropylmethyl-acetamido]-2-(morpholino-1-methylenyl)-4xe2x80x2-fluoroacetophenone.
(2E)-(2S-2-benzyloxycarbonylamino-2-phenylmethyl-acetamido)-3-(1-carbomethoxy-2-phenethylamino)-acrylamide
(2Z)-(2S-2-benzyloxycarbonylamino-2-phenylmethyl-acetamido)-3-(1-carbomethoxy-2-phenethylamino)-acrylamide
(2E)-(2S-2-benzyloxycarbonylamino-2-phenylmethyl-acetamido)-3-(1-carbomethoxy-methylamino)-acrylamide
(2E)-(2S-2-benzyloxycarbonylamino-2-phenylmethyl-acetamido)-3-(1-carbomethoxy-methylamino)-acrylamide
As stated, the compounds of the invention are inhibitors of cysteine proteases, for example cathepsins B, L, S and/or K. The invention therefore also provides a pharmaceutical composition containing a compound of formula (I) as defined above, and a pharmaceutically acceptable carrier. Also provided is the use of such a compound in the preparation of a composition for inhibiting cysteine protease activity in the body of a mammal suffering a disease mediated by such activity, and a method of treatment of an animal suffering from a disease mediated by cysteine protease activity, which method comprises administering to the mammal a sufficient amount of a compound of formula (I) as defined above to inhibit such activity.
Diseases mediated by cysteine protease activity include muscular dystrophy, osteoporosis, tumour metastasis, rheumatoid arthritis, neuronal or cardiac ischaemia, allergic immune response, and protozoal or bacterial disease.
Compositions with which the invention is concerned may be prepared for administration by any route consistent with the pharmacokinetic properties of the active ingredient(s).
Orally administrable compositions may be in the form of tablets, capsules, powders, granules, lozenges, liquid or gel preparations, such as oral, topical, or sterile parenteral solutions or suspensions. Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinyl-pyrrolidone; fillers for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricant, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants for example potato starch, or acceptable wetting agents such.as sodium lauryl sulphate. The tablets may be coated according to methods well known in normal pharmaceutical practice. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example sorbitol, syrup, methyl cellulose, glucose syrup, gelatin hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters such as glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p-hydroxybenzoate or sorbic acid, and if desired conventional flavouring or colouring agents.
For topical application to the skin, the active ingredients(s) may be made up into a cream, lotion or ointment. Cream or ointment formulations, which may be used for the drug, are conventional formulations well known in the art, for example as described in standard textbooks of pharmaceutics such as the British Pharmacopoeia.
The active ingredients(s) may also be administered parenterally in a sterile medium. Depending on the vehicle and concentration used, the drug can either be suspended or dissolved in the vehicle. Advantageously, adjuvants such as local anaesthetic, preservative and buffering agents can be dissolved in the vehicle. Intravenous infusion is another route of administration for the compounds.
Safe and effective dosages for different classes of patient and for different disease states will be determined by clinical trial as is required in the art. It will be understood that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, rate of excretion, drug combination and the severity of the particular disease undergoing therapy.
Compounds of the invention wherein A and B taken together represent a bond and R4 represents NH2 may be prepared by treatment of azetidin-2-ones of formula (IV) with ammonium hydroxide. 
wherein R11 is a leaving group such as phenoxy, acetoxy.
Compounds of the invention wherein A and B taken together represent a bond and R4 represents a primary or secondary amino group may be prepared by treatment of compounds (IV) with a primary or secondary amine, or by appropriate derivatisation of the amino group of the corresponding compounds wherein R4 is amino.
Compounds of the invention wherein A and B taken together represent a bond and R4 represents a hydroxy group may be prepared by treatment of compounds (IV) with acetic acid, for example at ambient temperatures. Compounds of the invention wherein A represents hydrogen and B and R4 represents a hydroxy group may also be prepared by treatment of compounds (IV) with acetic acid, but under less forcing conditions than for the alpha-beta unsaturated compounds, for example at low temperatures such as about 0xc2x0 C.
Compounds of the invention wherein A and B taken together represent a bond and R represents a substituted hydroxy group or a primary or secondary amino group may be prepared from the corresponding compounds wherein R4 is hydroxy or amino by appropriate derivatisation of that hydroxy or amino group. Likewise, compounds of the invention wherein A represents hydrogen and B and R4 are independently a substituted hydroxy group may be prepared from the corresponding compounds wherein B and R4 are hydroxy by appropriate derivatisation of one or both of those hydroxy groups.
Compounds of the invention wherein A and B taken together represent a bond and R4 represents an alkyl, alkenyl, alkynyl, cycloalkyl or aryl may be prepared by the following the synthetic scheme as depicted below in scheme 1. 
Compounds of the invention wherein A and B taken together represent a bond and R4 represents an alkoxy, aryloxy or cycloalkoxy may be prepared by the following the synthetic scheme as depicted below in scheme 2. 
In the above processes, the reactants are reacted together with solvent at elevated or low temperatures for sufficient time to allow the reaction to proceed to completion. The reaction conditions will depend upon the nature and reactivity of the reactants. Depending on the reactants, a solvent will generally be selected from the group consisting of benzene, toluene, acetonitrile, tetrahydrofuran, ethanol, methanol, chloroform, ethyl acetate, methylene chloride, dimethyl formamide, dimethyl sulfoxide, hexamethyl phosphoric triamide, water, pyridine, acetone and the like. Solvent mixtures may also be utilized.
Reaction temperatures generally range from between xe2x88x9270xc2x0 C. to 150xc2x0 C. The preferred molar ratios of reactants are 1:1 to 5. The reaction time range from 0.5 to 72 hours, depending on the reactants.
The azetidine-2-one strating materials (V) may be prepared by literature methods, including those in International patent applications WO 96/32408, WO 98/12176, WO 98/12210.